com.commonsware.android.fileseditor.EditorFragment.java Source code

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Here is the source code for com.commonsware.android.fileseditor.EditorFragment.java

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/***
  Copyright (c) 2012-2015 CommonsWare, LLC
  Licensed under the Apache License, Version 2.0 (the "License"); you may not
  use this file except in compliance with the License. You may obtain a copy
  of the License at http://www.apache.org/licenses/LICENSE-2.0. Unless required
  by applicable law or agreed to in writing, software distributed under the
  License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS
  OF ANY KIND, either express or implied. See the License for the specific
  language governing permissions and limitations under the License.
      
  Covered in detail in the book _The Busy Coder's Guide to Android Development_
https://commonsware.com/Android
 */

package com.commonsware.android.fileseditor;

import android.graphics.Rect;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.text.Editable;
import android.text.method.PasswordTransformationMethod;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.EditText;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.Writer;

public class EditorFragment extends Fragment {
    private static final String KEY_FILE = "file";
    private EditText editor;
    private LoadTextTask loadTask = null;
    private boolean loaded = false;

    static EditorFragment newInstance(File fileToEdit) {
        EditorFragment frag = new EditorFragment();
        Bundle args = new Bundle();

        args.putSerializable(KEY_FILE, fileToEdit);
        frag.setArguments(args);

        return (frag);
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setRetainInstance(true);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View result = inflater.inflate(R.layout.editor, container, false);

        editor = result.findViewById(R.id.editor);
        editor.setTransformationMethod(new DummyTransformationMethod());

        return (result);
    }

    @Override
    public void onViewCreated(View view, Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);

        if (!loaded) {
            loadTask = new LoadTextTask();
            loadTask.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR,
                    (File) getArguments().getSerializable(KEY_FILE));
        }
    }

    @Override
    public void onPause() {
        if (loaded) {
            new SaveThread(editor.getText().toString(), (File) getArguments().getSerializable(KEY_FILE)).start();
        }

        super.onPause();
    }

    @Override
    public void onDestroy() {
        if (loadTask != null) {
            loadTask.cancel(false);
        }

        super.onDestroy();
    }

    private class LoadTextTask extends AsyncTask<File, Void, String> {
        @Override
        protected String doInBackground(File... files) {
            String result = null;

            if (files[0].exists()) {
                BufferedReader br;

                try {
                    br = new BufferedReader(new FileReader(files[0]));

                    try {
                        StringBuilder sb = new StringBuilder();
                        String line = br.readLine();

                        while (line != null) {
                            sb.append(line);
                            sb.append("\n");
                            line = br.readLine();
                        }

                        result = sb.toString();
                    } finally {
                        br.close();
                    }
                } catch (IOException e) {
                    Log.e(getClass().getSimpleName(), "Exception reading file", e);
                }
            }

            return (result);
        }

        @Override
        protected void onPostExecute(String s) {
            editor.setText(s);
            loadTask = null;
            loaded = true;
        }
    }

    private static class SaveThread extends Thread {
        private final String text;
        private final File fileToEdit;

        SaveThread(String text, File fileToEdit) {
            this.text = text;
            this.fileToEdit = fileToEdit;
        }

        @Override
        public void run() {
            try {
                fileToEdit.getParentFile().mkdirs();

                FileOutputStream fos = new FileOutputStream(fileToEdit);

                Writer w = new BufferedWriter(new OutputStreamWriter(fos));

                try {
                    w.write(text);
                    w.flush();
                    fos.getFD().sync();
                } finally {
                    w.close();
                }
            } catch (IOException e) {
                Log.e(getClass().getSimpleName(), "Exception writing file", e);
            }
        }
    }

    private static class DummyTransformationMethod extends PasswordTransformationMethod {
        @Override
        public CharSequence getTransformation(CharSequence source, View view) {
            return (source);
        }

        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {
            // no-op
        }

        @Override
        public void onFocusChanged(View view, CharSequence sourceText, boolean focused, int direction,
                Rect previouslyFocusedRect) {
            // no-op
        }

        @Override
        public void afterTextChanged(Editable s) {
            // no-op
        }

        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {
            // no-op
        }
    }
}